Abstract: A practical mathematical model for microbial flooding was presented.In order to make the description simplified,the complex biologic,physical and chemical behaviors of microbial flooding were simulated.The equations for describing microbial growth,nutrient consumption and metabolize production were proposed.The equations for characterizing dispersion and adsorption for species flowing through a porous medium were also established.In this model,the reciprocities of microbe and metabolize production with rock,oil and water were considered.In order to quickly predict the production performance, the streamline method was employed to solve this model as an alternative to the traditional finite-difference method.Based on streamline distribution of steady-state flow through media in the complex boundary confirmed with the boundary element method (BEN),the one-dimensional flow problem was solved.The saturation equation was solved using an explicit total variation diminishing (TVD) method.To ensure the calculation stability of concentration equation,Crank-Nicolson difference format was used in spatial discretization, and variable in retention coefficient discretization was quasi-linear idsposed. This model has the advantages of a little information,fast calculation and adaptation for determining the microbial drive performances of all kinds of patterns in a random shaped porous media with assembly boundary.It is an effective tool for screening in the early stage and dynamic management of reservoir in the microbial flooding oilfield.

Key words: microbial flooding, boundary element method, streamline method, enhanced oil recovery, mathematical model

摘要： 建立了一种实用的微生物驱油数学模型,在力求对模型简化描述的同时,较为全面地考虑了驱替过程的主要生化、渗流机理.论述了微生物在油层中的生长、代谢和基质消耗状况.考虑了扩散和吸附,建立了描述微生物菌体、营养液、代谢产物在油层中的运移方程,同时对微生物及其代谢产物与岩石、油、水的相互作用以及所引起的各种物理化学变化进行了研究.为了实现生产动态的快速预测,用流线方法替代传统的有限差分法求解该模型.在结合边界元方法确定复杂边界条件下稳态渗流场流线分布的基础上,对流管内的一维渗流问题进行了求解.应用显式全变差递减(TVD)法求解了饱和度方程.在浓度方程求解过程中,空间项离散采用Crank-Nicolson差分格式,对滞留项系数变量进行了拟线性处理,保证了计算的稳定性.该模型输入参数较少、计算速度快,适应于对任意形状边界条件下各种井网配置的微生物驱油动态的计算,是油田微生物驱油的早期筛选及油藏动态管理的有效工具.

关键词: 微生物驱, 边界元法, 流线方法, 提高采收率, 数学模型